From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Test report on an Ediswan ammeter with a 150 ampere shunt.
| Identifier | ExFiles\Box 165\3\ img059 | |
| Date | 12th June 1925 | |
| X9756 86033 To SFT{Mr Swift}/Mr. Brock. EFCL/T12.6.25. EDISWAN AMMETER WITH 150 AMPERE SHUNT. We have tested this instrument with the leads supplied, but it should be noted that a variation in the leads may upset the readings, and we suggest you fix cable ends to these leads with their present lengths and retain them for the purpose. We find the instrument to be irregularly incorrect at under 30 amperes. Above 30 amperes the scale is reasonably proportional and the average correction consists of 1.5% addition to every reading; the resulting error is then reasonably within ± 1/2% We return the instrument herewith. EFC. | ||